Insulator



April 8 1924.

L. STEVINBERGER INSULATOR Filed June l2, 1919 2 Sheets-Sheet 2 nvm/TUR LOU/5 Sife/berger Br t MTWR/v;

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Patented Apr. 8, 1924.

LOUIS STEINBERGER, OF BROOKLYN, NEW YORK. y

INSULATOR.

Application filed June 12, 1919. Serial o. 303,723.

To all lwhom t may concern.'

Be it known that- I, Loms STEINBERGER,

a citizen of the United States, and a resident of the borough of Brooklyn, city and State of New York, have invented certain new and useful Improvements in Insulators,` of which the following is a specification.

This invention relates especially to an improved and novel type of insulator for use in conjunction with ordinary lightning arresters of transformers or other electrical apparatus to prevent damage or destruction thereof by a high frequency electrical disturbance, such as lightning.

One of the objects of the invention is to construct an insulator, the conducting element of which is provided with an electromagnetic choking coil structure for the purpose of retarding any rush or surge of elec- 29 tric current due to a stroke of lightning, or other high frequency electrical disturbances. Another object is to provide an insulator in which the conductor is connected with a magnetic choking structure, said structure rounded by static shields.

Another object is to provide an insulator in which the conductor is connected with a choking coil surrounded by a magnetic sleeve 30 within the body vof `the insulator.

lVith the foregoing and other objects in view which will appear from the description and claims, the invention resides in the combination and arrangement of parts andv in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein described can be made `Within the scope of that which is claimed, without departing from my invention.

As will be clearly hereinafter understood,

an insulator embodying my invention and thus provided with, an electro-magnetic choking structure is especially useful in conjunction with ordinary lightning arresters in connection with transformers, switches or other electrical apparatus, for the reason that said apparatus is protectedr from damage or destruction by high frequency currents.

The ma etic chokin device which I have provi ed will retar the instantaneous rush or surge of electrical current to the electrical apparatus in the event that the conductor paing throughy the insulator is being within the body of the insulator surcharged by a stroke of lightning or other high frequency electrical disturbance of similar nature, thus protecting the above mentioned electrical apparatus in such an event by affording a lightning arrester .for instance, sufficient opportunity to act before the high frequency current can pass by the choking device. i I

By means of my invention, therefore, an abnormally high voltage current is prevented from passing to the electrical'equipment, while an ordinary current .will flow along the conductor, past the choking device Without difficulty, Where the number of turns of the helix forming the choking device is of proper ratio to the amoimt of current -.flowing through the conductor. When lightning or other similar electrical dis turbances pass along the line, the conditions are reversed, for the reason that a stroke of lightning or an equivalent high frequency electrical current will leave a complete metallic path of low ohmic resistance and will jump an air gap, Whilea normal line current will not jump but will continue to pass; along the metallic path including the magnetic chokingdevice within the insulator. This result is due to the hi h self induction set up in the ma netic c cking device by currents of a hig ly oscillatory character, such as those produced by lightning strokes.

Referring to the drawings in which the same reference character indicates the. same part in the several views:

' Fig. 1 is a vertical section (with parts in elevation) of an insulatorembodymg my invention'. l

Fig. 2 is a section on line 2-2 of Fig. 1. Fig. 3 is afragmentary view in section of a detail showing a tubular conductor.

Fig. 4 is a vertical section of an insulating housing for the choking coil. In the particular embodiment of my invention there is provided an elongated body A of any suitable moldable insulating material, preferably that material known in the art as electrose, which body is molded Within a combined supporting ring B and -static shield C, the latter being situated substantially between the ends thereof. Embedded axially within the body A is a. conductor 10, provided with a choke coil 11, the said choke coil being surrounded by a magnetic sleeve of iron or steel 20, the said llo choke coil and magnetic sleeve being seated centrally of the static shield C.

Referring to the construction more in detail, the body A of insulating material has molded or embedded axially therein a conductor 10 extending from the body at each end at 13 an 14, to which are rpectivel secured the line wire clamps 15 and 16 whic i are constructed to fit over the ends of the portions 13 and 14 and rest against the Washers W at each end of the insulator andwhich are secured in place by lock nuts N and N, all as clearly shown. The conductor may be either a. solid rod or a tube of metal. A

The solid rod construction is illustrated in Fig. 1 and a modified structure which I contemplate using when the conductor is a tube, is illustrated in Fig. 3.

The conducting rod 10 is formed into a coil 11 situated centrally thereof, the coil being of such maximum diameter and length as to freely fit within a magnetic sleeve 20 of iron or steel, as shown. The magnetic sleeve 20 immediately surrounds the coil 11 of the conductor and has a maximum length slightly exceeding the length of the coil and substantially equal to the length of the static shield which, in turn, surrounds the magnetic sleeve.

Each end of the magnetic sleeve 2O is provided with internal screw-threads 21 and 22 arranged to engage with the screw-threads 31 and 32 provided on the outer surface of plugs 30 and 35 of insulating material, as shown.

Within the magnetic sleeve 20 and filling the space between the plugs of insulating material 30 and and the magnetic coil 20, is a layer of insulating material 40, such as pitch which fiows readily when hot and which sets when cold so that the coil is immediately surrounded by a layer of insulating material.

Instead of embedding the coil Within a cover of plastic insulating material 40 as `iust described, I contemplate using a structure similar to that shown in Fig. 4, Where an elongated tube or receptacle 40 of insulating material is provided, having a bottom 41 in which a hole 42 is provided for the conductor. Within this insulating tube or casing 40 fits the coil 20, and a. plug 530 of insulating material having a hole 43 in the center thereof for the passage of the conductor 10. is fitted by screwthreads into the mouth of the receptacle 40 which is pro-V vided With screw-threads on the inner surface thereof for that purpose.

As will be readily understood, the choke coil 11 is fitted inside of the insulating housing 40 which is then closed by the plug 30. The housing is placed inside of the magnetic sleeve 2O of iron or steel, as shown, and this assemblage of parts is molded or embedded within the central portion of the insulator body A in such position as to be surrounded by the static shield C.

When the conductor is formed of a tube, both ends are open to the air so as to provide for the passage of a current of air through the tube, thus a'ording a cooling medium for the central portion of the insulator.

The line wire clamp is fitted to the tube in a manner similar to the construction shown in Fig. 1, where the conductor is a solid rod. Then the tube structure is used, however, the tube is made to extend above the nuts N a sufiicient distance upon which a cap is fitted by means of an internal screw-threaded cavity T1 engaging the screw-threads 72 on the upper outside portion of the conducting tube. The cap is provided with a skirt or fiange portion 75 extending over the series of holes T0 formed in the tube above the nuts so as to permit of ready circulation of air through the center of the insulator, all as will be clearly understood. Any other suitable cooling medium may be employed to accomplish similar results.

From what has been said above, it will be appreciated that the coiled portion of the conductor disposed within the iron or steel body Q0 provides the choking effect, due to the fact that a high frequency current will set up magnetic fields in the sleeve Q0 which resist the flow of the high frequency current.

The magnetic sleeve 2O is of such formation and is associated with the conductor in such a way that in the presence of a high frequency current the magnetic field set up in the sleeve is proportionate to the flow of the current. A sufficient period of time is thus consumed during which the potential builds up between the magnetic clicking device and the apparatus to a point sufliciently high to cause the lightning arrester, for instance, to discharge and carry the current to ground. Thus the apparatus is relieved from the great strain to which it would otherwise be subjected by an abnormally high frequency current passing along the line, and damage and the consequent expense due to the breaking down of the apparatus is greatly lessened or entirely obviated.

As will be readily appreciated. the static shields C provide means 'for redistribution of the electro-static stresses within the body of the insulator` thereby tending to lengthen the life of the insulator.

Insulators can be constructed in different sizes and proportions for currents of different voltages, and are adapted to supersede the more expensive and less efficient choke coils now used.

As changes of construction could be made Within the scope of my invention, it is ina conductor molded therein having a portionv tended that all matter contained in the above description or shown in the accompanying drawings shallbe interpreted as illustrative and not in a limiting sense.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a device of the class described, a body of insulating material and an electrical conduotor therein having a coiled ortion surrounded by magnetic material or dissipating the effect of surges of static charges flowing through the conductorby lightning strokes or the like.

2. In a device of the class described, a body of insulatingmaterial and an electrical conductor molded therein and having a eentrally disposed helical portion forming a choke coil and a magnetic meansfor increasing vthe choking effect of said coil for neutralizing the effect of static char es induced in said conductor by abnorma electrical disturbances.

3. In' a device of the class described, a body of insulating material and an electrical conductor molded therein and provided with a magnetic choking structure to .retard an rush or surge of an electric current of hig frequency set up in the conductor by abnormal electrical disturbances.

' 4.1m a device of the class described, a body of insulatin material end an electrical conductor molde ,therein havlng a colled portion for dissipating the effect of abnor-` mal electrical stresses induced in the conductor, and a magnetic sleeve associated with said coiled portion of the conductor` and coacting therewith to assist in building u a magnetic field when abnormal electr1ca`l stresses are induced in the conductor.

5. In a device of theclass described, Aa body of insulating material, an electrical vthereof shaped to form a choke coil, and a magnetic sleeve surroundin said choke coil and moldedwithin said bo 4.of insulatlng material, said chokel c'oil an said magnetic sleeve being -arran ed to jointly buildup a magnetic field to ampen the efl'ect of electrical stresses set u in said conductor by abnormal electrical isturbances.

6. In a device of the class described, a body of insulating material, an electrical conductor molded therein having a portion June, 1919.

thereof shaped to form a choke coil, and a magnetic sleeve surrounding said choke coil and molded within said body of insulating material, and a supportingl ring having a kmal electrical stresses induced in the conductor and a magnetic means also molded 1n said body of insulating material in a manner to'lncrease the action l portion.

8. In a device of the class described,'a body of insulating material and a hollow electrical conductor molded therein and having a coiled portion for dissipatingI the effect of abnorma electrical stresses induced in the `conductor, said conductor being arran ed to permit the circulation of cooling Hui Itherethrough.

trical conductor molded therein and having a coiled portion for dissipating the effect of abnormal electrical stresses induced in the conductor, said conductor being arranged to permit the circulation of cooling fluid therethrough and caps covering the ends of said conductor. i

10. In a device of theclass described, a body of insulating material, an electrical -conductor molded therein and having ai coiled portion for dissipating the effect of abnormal electrical stresses induced in the conductor and an enclosing means of magnetic material f or said coiled portion and insulated therefrom material.

.In witness whereof, I have hereunto set y hand atthe borouYghof Manhattan, city and State of New ork, this 6th day of `Louis STEINBERGER.

l In presence of- Imm. R. Fmrcnm molded in said insulating v' of said coiled a device of the class described, a .body of insulating material, a hollow elec- 

